PROJECT SUMMARY Background. In order to end the AIDS epidemic by 2030, the health needs of adolescents and young people (AYA) aged 15 to 24 years living with HIV must be met. Antiretroviral therapy adherence is one of the most notable barriers to desired health outcomes in this population. Understanding and engaging the family and household level is imperative for AYA living with HIV to achieve viral suppression. Study Goal and Aims. The goal of this study is to better understand how family and household level factors relate to and influence the self-management of HIV among AYA living with HIV in Ndola, Zambia. The specific aims of this study are: (1) To qualitatively understand caregiver experiences with AYA who are transitioning to HIV self-management. (2) To quantitatively assess how AYA?s perceived family connectedness is associated with viral suppression in the context of HIV self-management. (3) To qualitatively explore modifiable family and household level influences on AYA self-management of HIV. This work is in line with NIMH high priority areas to advance the development of interventions delivered beyond the individual level and to improve HIV treatment outcomes through optimal treatment adherence and sustained engagement in care. Approach. This explanatory, sequential mixed-methods study will leverage the data and infrastructure of a completed parent study, an individually-randomized controlled trial that assessed the impact of a 6-month peer- mentoring intervention with a caregiver support component on HIV outcomes among AYA living with HIV in Ndola, Zambia. Aims 1 and 2 are secondary analyses of qualitative and quantitative parent study data, respectively. Aim 1 will be an inductive and deductive thematic qualitative analysis of in-depth interviews (IDIs) from 23 caregivers of AYA participants. Aim 2 will develop a structural equation model using baseline data from 260 HIV-positive AYA participants from the parent study; this will quantify and explain associations between family connection and viral suppression. Aim 3 will require primary qualitative data collection; up to two new IDIs will be conducted with approximately 20 AYA parent study participant and caregiver dyads. These individual interviews will build upon findings from Aims 1 and 2 and will be analyzed using a thematic approach akin to Aim 1. Findings from Aims 1-3 will be triangulated to develop a more nuanced understanding of this important topic. Fellowship Information. The proposed research will serve as the doctoral dissertation of Ms. Kirsty Sievwright, a PhD student at Johns Hopkins Bloomberg School of Public Health. The training is guided by one Sponsor, three Co-Sponsors, and one Scientific Advisor with complementary topical, theoretical, and methodological expertise, including in research with AYA living with HIV. The training plan combines formal coursework, ongoing mentorship, field research, and other opportunities to prepare Ms. Sievwright to become a leading independent researcher in the social and behavioral sciences, focused on HIV prevention, care, and treatment among AYA.